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PubMed1982

The value of a single serum progesterone measurement in the midluteal phase as a criterion of a potentially fertile cycle ("ovulation") derived form treated and untreated conception cycles.

A single midluteal serum progesterone concentration was obtained in 212 untreated cycles in 113 infertile patients, including 138 cycles in 72 patients in whom tubal, seminal, and cervical causes of infertility had been excluded. There were 16 conception cycles in the latter group. In an extended study a total of 21 untreated singleton conception cycles have been observed with a mean progesterone value of 40.7 nmol/l (12.8 ng/ml), 95% confidence limits of 28 to 53 nmol/l (8.8 to 16.7 ng/ml), and a range of 27 to 53 nmol/l (8.5 to 16.7 ng/ml), which extended significantly above as well as below the conception range, indicating that there is an optimal range for fertility with both an upper and a lower limit. The lower limit is of greater practical importance; and, partly to allow for assay variation, we suggest it should be taken as 30 nmol/l (9.4 ng/ml). It provided a clinically reliable criterion of potential fertility ("ovulation") in related studies. Our findings in treated conception cycles suggest that a higher value may be needed after treatment with clomiphene or gonadotropins because of the contribution from other stimulated follicles.

Adult↗
PubMed1989

Interobserver variation in estimation of day of conception intercourse using selected natural family planning charts.

In order to study outcome of pregnancy related to timing of conception it is necessary to have both markers of ovulation and records of intercourse. Natural family planning (NFP) charts where the woman records basal body temperature (BBT) and mucus signs are ideal for this purpose. Much work has been done relating timing of BBT and mucus signs to ovulation, but very little work has been done to examine interobserver agreement on the interpretation of these signs. Four NFP experts examined 28 NFP pregnancy charts to determine the BBT rise, the mucus peak, and two most likely days of conception intercourse. The charts were selected because they provided difficulties in interpretation. The reviewers were able to agree on the most probable day of conception intercourse in 96.4% of cases, on the mucus peak in 74.1% of cases, and on the interval between the most probable conception intercourse and mucus peak in 70.4% of cases. There was poor agreement on the first day of the BBT rise (38.5%). The authors conclude that in selected difficult NFP charts, the mucus peak is a more valid indirect measure of ovulation both because it is subject to less interobserver variation and because it more closely approximates the timing of ovulation.

Body Temperature↗
PubMed1989

Human chorionic gonadotropin, estradiol, and progesterone profiles in conception and nonconception cycles in an in vitro fertilization program.

In 22 consecutive in vitro fertilization cycles stimulated with purified follicle-stimulating hormone, human chorionic gonadotropin (hCG), estradiol (E2), and progesterone (P) were measured every 3 days during the luteal phase. All serum measurements were normalized to the day of hCG administration (day 0). There was a total of nine pregnancies; two were biochemical pregnancies, whereas 7 of the 22 women had clinical pregnancies (31.8%). Of these, two miscarried and five had term pregnancies (three singleton, two twin). Conception cycles could be differentiated from nonconception cycles by serum E2 levels on day 8 (P = 0.035), by hCG levels on day 11 (P = 0.03), and by P levels on day 14 (P = 0.001). From days 8 to 11, hCG levels plateaued in conception cycles and decreased in nonconception cycles. However, during that period, E2 and P fell in both groups of women. This decline in sex steroids, which was observed in both conception and nonconception cycles, may well negatively influence endometrial development during the peri-implantation period and compromise conception, resulting in failure to conceive, biochemical pregnancy, and early miscarriage.

Adult↗
PubMed2003

Peer support within a health care context: a concept analysis.

Peer support, and the integration of peer relationships in the provision of health care, is a concept of substantial significance to health scientists and practitioners today, as the focus shifts from the treatment of disease to health promotion. If the nursing profession is to effectively incorporate peer relationships into support-enhancing interventions as a means to improve quality care and health outcomes, it is essential that this growing concept be clearly explicated. This paper explores the concept of peer support through the application of Walker and Avant's (Strategies for Theory Construction in Nursing, 3rd Edition, Prentice-Hall, Toronto, 1995) concept analysis methodology. This analysis will provide the nursing profession with the conceptual basis to effectively develop, implement, evaluate, and compare peer support interventions while also serving as a guide for further conceptual and empirical research.

Emotions↗
PubMed1997

Caring: dealing with a difficult concept.

The concept of caring is the focus of this paper, in which an attempt is made to clarify the meaning of caring in nursing using one method of concept analysis. The decision to complete an analysis on caring was made following a substantial review of the literature, from which a concise definition of the concept remained elusive. Concept analysis as described by Walker and Avant (1995) is utilised and this paper demonstrates the various steps involved in this approach.

Adult↗
PubMed2002

From the traditional concept of safety management to safety integrated with quality.

This editorial reviews the evolution of the concepts of safety and quality that have been used in the traditional workplace. The traditional programs of safety are explored showing strengths and weaknesses. The concept of quality management is also viewed. Safety management and quality management principles, stages, and measurement are highlighted. The concepts of quality and safety guarantee are assessed. Total Quality Management concepts are reviewed and applied to safety quality. Total safety management principles are discussed. Finally, an analysis of the relationship between quality and safety from data collected from a company in Spain is presented.

Humans↗
PubMed2000

The critical loads concept: milestone or millstone for the new millennium?

The significance of the introduction of the critical loads concept in the closing decades of the 20th century is considered critically, both in the context of its potential in planning pollution abatement strategies over a range of regional spatial and temporal scales and in terms of its more general impact upon atmospheric pollution effects research. Based upon perceived strengths and shortcomings of the concept and of the ways in which it has thus far been applied, a brief assessment is made also of its possible role in the opening decade of the new millennium. It is concluded that the validity of some of the fundamental underpinning concepts and of the data being used for their application could, and should, be questioned. Nevertheless, environmental pollution management and abatement policy planning will continue to require application of the critical loads concept or something very similar, both in existing and novel areas of application, for the sustainable management of soil and water resources in the long term.

Forestry↗
PubMed2003

Conception rates of dairy cows following early not-pregnant diagnosis by ultrasonography and subsequent treatments with shortened Ovsynch protocol.

Our objective was to determine the feasibility of prompt reinsemination of dairy cows when diagnosed not pregnant 27-29 days after first-service timed AI (TAI). We assumed that a first-wave dominant follicle was present at that time that would ovulate in response to GnRH once precocious luteal regression was induced after administration of PGF(2alpha). Cows that had not been detected in estrus and reinseminated by Days 27-29 after a first-service TAI were diagnosed not pregnant by ultrasonography. Nonpregnant cows from three herds were assigned randomly to receive either no further treatment until reinsemination (controls; n=189); 25mg i.m. of PGF(2alpha) and then reinsemination according to detected estrus (81 of 108) or at 72-80h after PGF(2alpha) treatment (PGF) in the absence of estrus (27 of 108); or 25mg i.m. of PGF(2alpha) followed by 100 microg i.m. of GnRH 48h later (PGF+GnRH) and then reinsemination after detection of estrus (9 of 160) or at 16-20h after GnRH (151 of 160). Blood samples were collected at the time of the not-pregnant diagnosis and again 48h later. Concentrations of progesterone before treatment with PGF(2alpha) were elevated (<1ng/ml) in 61% of the cows when PGF(2alpha) was administered and 81% of the cows given PGF(2alpha) had low (<1ng/ml) concentrations of progesterone 48h after PGF(2alpha). Treated cows were re-inseminated earlier (P<0.01; 31+/-1days) after first-service TAI than controls (55+/-1days). Conception rates after treatment were not different among treatments: PGF (22%), PGF+GnRH (23%), and control (23%). Average intervals from calving to conception were 22-23 days less (P<0.001) in treated cows than in controls. We concluded that treating nonpregnant cows with PGF(2alpha) on Days 27-29 after insemination produced acceptable conception rates when inseminations were made after detected estrus or when TAI was used after GnRH treatment. Further, both treatments reduced days between first-service TAI and second inseminations, and days from calving to conception.

Animals↗
PubMed2004

Improved conception in timed-artificial insemination using a progesterone-releasing intravaginal device and Ovsynch protocol in postpartum suckled Japanese Black beef cows.

The primary objective was to determine the effect of supplemental progesterone, administered via an intravaginal device (CIDR), on conception rates to timed-artificial insemination (timed-AI) in postpartum suckled Japanese Black beef cows treated with the Ovsynch protocol. A secondary objective was to compare the effects of treatments on plasma concentrations of progesterone and estradiol. Cows in the control group (Ovsynch, n=38) received a standard Ovsynch protocol (100 microg GnRH analogue on Day 0, 500 microg PGF2alpha analogue on Day 7, and 100 microg GnRH analogue on Day 9), with AI on Day 10, approximately 20 h after the second GnRH treatment. Cows in the treatment group (Ovsynch+CIDR; n=40) received a standard Ovsynch protocol plus a CIDR for 7 days (starting on Day 0). Plasma progesterone concentrations were determined on Days 0, 1, 7, 9, 10, and 17 and plasma estradiol-17beta concentrations were determined on Days 7, 9, 10, and 17. The odds ratio for likelihood of conception was 3.29 times greater (P=0.02) in the Ovsynch+CIDR group compared to Ovsynch group. The conception rate was greater (P=0.03) in the Ovsynch+CIDR group than in the Ovsynch group (72.5% versus 47.7%). Insertion of a CIDR device significantly increased plasma progesterone concentrations only on Days 1 and 7 (P<0.001 and P=0.05, respectively), but had no significant effect on plasma estradiol-17beta concentrations. Including a CIDR with the Ovsynch protocol significantly improved conception rates in postpartum suckled Japanese Black beef cows.

Administration, Intravaginal↗
PubMed1994

Association of pregnancy-induced hypertension with duration of sexual cohabitation before conception.

Pregnancy-induced hypertension affects at least 10% of all pregnancies. An association with first pregnancy or a change in paternity for subsequent pregnancies has been suggested. We studied the duration of sexual cohabitation with the father prior to conception and the incidence of pregnancy-induced hypertension. During a five-month period, 1011 consecutive women who delivered in an obstetric unit were interviewed about paternity and duration of sexual cohabitation before conception. Obstetric charts were abstracted to identify three groups: those with pregnancy-induced hypertension, chronic hypertension, and normal blood pressure. The incidence of pregnancy-induced hypertension was 11.9% among primigravidae, 4.7% among same-paternity multigravidae, and 24.0% among new-paternity multigravidae. For both primigravidae and multigravidae, length of sexual cohabitation before conception was inversely related to the incidence of pregnancy-induced hypertension (p < 0.0001). Similar results were observed after control for race, education, maternal age, marital status, and number of pregnancies. Pregnancy-induced hypertension may be a problem of primipaternity rather than primigravidity. Furthermore, an extended duration of sexual cohabitation before conception may protect against pregnancy-induced hypertension.

Adolescent↗
PubMed2001

Bipolarity from ancient to modern times: conception, birth and rebirth.

We review the history of bipolar disorders from the classical Greek period to DSM-IV. Perhaps the first person who described mania and melancholia as two different phenomenological states of one and the same disease was the Greek physician of the 1st century AD, Aretaeus of Cappadocia. The modern concept of bipolar disorders was born in France, with the publications of and. Emil Kraepelin, however, in 1899, unified all types of affective disorders in 'manic-depressive insanity'; in spite of some opposition, Kraepelin's unitary concept was adopted worldwide. In the 1960s, however, the rebirth of bipolar disorders took place through the publications of Jules Angst, Carlo Perris, and George Winokur, who independently showed that there exist clinical, familial and course characteristics validating the distinction between unipolar and bipolar disorders; in addition, they verified several of the corresponding opinions of the Wernicke-Kleist-Leonhard school. The concept of unipolar and bipolar disorders has further advanced in the last three decades: landmark developments include the renaissance of Kraepelin's mixed states and of Kahlbaum's and Hecker's cyclothymia and related affective temperaments, the concept of soft bipolar spectrum (Akiskal), and the distinction of schizoaffective disorders into unipolar and bipolar forms.

Bipolar Disorder↗
PubMed1998

Interactions between the associations of parity, lactation length, and weaning-to-conception interval with subsequent litter size in swine herds using early weaning.

Sixteen farms having an average lactation length between 14.9 and 18.9 days were selected based upon producers' willingness to keep records of production and lactation feed intake. Data contained 9162 subsequent litter-size records abstracted from computerized production information-system files and lactation feed-intake records. Two-way interactions between the associations of parity and lactation length, and parity and weaning-to-conception interval with subsequent litter size were found in the same statistical model. Subsequent litter size did not increase in parities 1 and 2 as lactation length increased--but subsequent litter size in sows of parities 3-6 increased. In only parity 1, sows with weaning-to-conception interval 6-12 days produced 0.5 fewer pigs at subsequent farrowing than those with weaning-to-conception interval 1-5 days. However, in multiparous sows, no difference in subsequent litter size was found between weaning-to-conception intervals 1-5 and 6-12 days.

Animals↗
PubMed1997

Role concepts and expectations of physicians and nurses in hospitals.

The social environment in which hospitals in the Netherlands have to function nowadays is greatly changing. Over the last 10 years the policy of the Dutch government has become less directive, market mechanisms are gaining weight and the demand for services by patients is changing. As a result of these changes hospitals formulate their strategic goals in terms of improvement of quality of care and efficacy. A basic assumption in this article is that quality of care is to be gained by collaborative practice between physicians and nurses. A necessary condition for this is that there is a correspondence in role concepts and expectancies of physicians and nurses in hospitals. The object of this research is to describe the role concepts and role expectations of nurses, physicians and patients in two Dutch hospitals. In general, the research revealed considerable differences between role behaviour and role concepts among nurses. In the long run these differences may not be favourable for good understanding between them and physicians, or for their own job satisfaction. This may also have negative consequences for collaboration between nurses and physicians and, finally, for the quality of care and cure within the ward. There is a need for discussion of the role concepts of nurses in relation to their actual regular tasks in order to resolve this. A second discrepancy exists between the role behaviour of physicians and the expectations of nurses about this behaviour. This may also lead to a lower job satisfaction for nurses. Taking into account the fact that patients are satisfied with the way physicians and nurses pay attention to most aspects of care and cure, a discussion between physicians and nurses could be recommended. The aim is revising either the role behaviour of physicians, especially as regards their attention to the psycho-social needs of patients, or the expectations of nurses, or both.

Health Services Research↗
PubMed2003

Can the premises of the spasm of resistance vessel concept permit improvement in the treatment and prevention of ischemic heart disease?

In this communication, the spasm of resistance vessel (S-RV) concept of ischemic heart disease (IHD) and other ischemic will be reviewed and updated, and evidence will be presented that principles of the hypothesis might improve the treatment and prevention of IHD. The S-RV concept provides a different basic pathogenetic framework for IHD, and suggestions for treatment and prevention stem from its different basic conceptualization of this disorder. The concept asserts that S-RV directly induces symptoms in IHD, and this position challenges the accepted pathogenetic mechanism for this disorder, i.e., that symptoms in IHD are due directly to obstructive occlusions of epicardial arteries secondary to coronary artery disease. The S-RV concept avers that ischemia-induced S-RV is a major factor in IHD, and evidence supporting this position is provided. Another major position of the hypothesis is that no-reflow (reduced flow after infarction and severe myocardial ischemia in the absence of infarction) is due to ischemic injury-induced S-RV, and a variety of evidences to support this position are offered.Proposed improvement in the treatment of IHD is based mainly on treating ischemia-induced S-RV. alpha-Adrenergic sympathetic blockade reverses ischemia-induced S-RV, and alpha-adrenergic blockade is suggested as therapy for acute coronary syndromes and to prevent complications of percutaneous coronary interventions. Also, angiotensin-converting enzyme inhibition, which has actions similar to alpha-adrenergic blockade, is also suggested. Proposals for the prevention of IHD are based the prevention of S-RV, and special emphasis is given to preventing exercise- and stress-related IHD.

Acute Disease↗
PubMed2002

Relationships among milk progesterone, concentrate allocation, energy balance, milk yield and conception rate in Norwegian cattle.

Relationships among milk progesterone, concentrate allocation, energy balance (EB), milk yield and conception rate were studied in 146 lactations in 94 moderate yielding cows. All animals were of the dual purpose breed Norwegian cattle, and were monitored through their first and second lactations. The cows were assigned three different concentrate allocations and had free access to grass silage. Energy balance was estimated by subtracting energy required for maintenance and lactation from energy intake. Milk progesterone concentration was determined three times weekly from calving until pregnancy. The cumulative progesterone concentration was calculated as area under the progesterone curve for the first three luteal phases postpartum. The conception rate increased linearly by rising milk progesterone for values of cumulative progesterone in the lowest third of the range, whereas the likelihood of conception did not differ between milk progesterone concentrations within the upper two-thirds. This implies that the progesterone values were below a threshold value for optimal reproductive success in one-third of the services performed in this study. Milk progesterone concentrations during the third luteal phase postpartum were low when the high-energy diet was fed. Negative EB was associated with reduced values for milk progesterone during the third luteal phase in second parity cows. Likewise, milk yield was inversely related to progesterone levels during both the first and third luteal phases postpartum in second parity cows. Energy balance was higher and milk yield lower during peak lactation among second parity cows that conceived compared to cows that remained open after the first artificial insemination. The present study have demonstrated an association between likelihood of conception and the energy coverage in Norwegian cattle. This relationship is possibly mediated through progesterone deficiency.

Animals↗
PubMed2004

The biopsychosocial model in medical research: the evolution of the health concept over the last two decades.

The object of this study was to assess the change towards a biopsychosocial health concept among medical researchers in the last two decades, after the explicit criticism of the biomedical model in the late 1970s because of its somatic reductionism. The concepts of 'health' or 'healthy status of an individual' as reported as variable in empirical articles published in the journal The Lancet over the years 1978-1982 (period a) and 1996-2000 (period b) were searched by means of Medline and compared for their definition of these variables. None of the 52 examined papers set out a positive and replicable definition of 'health' (seven papers) or 'healthy status' (45). No difference was found between the two periods studied except for the failure of reports to describe 'healthy status' at all (65.5% in a, 19% in b). Most articles do it in an indirect way, namely through exclusion conditions of subjects taking part in treatment or control groups. Only three studies include psychological dimensions in their measures of 'healthy status' (two in a, one in b). Concerning 'health', all seven examined papers include psychological or both psychological and social dimensions. Although a change towards a more holistic concept of health has occurred in academic and institutional contexts over the last few decades, there does not appear to have been a parallel change in the practical domains of medicine. Possible reasons are discussed, specially the difficulty of applying the biopsychosocial model in medical care and the difficulty of competing with the traditional biomedical concept of health, which has proved fruitful and dominant in medicine over the past three centuries.

Attitude of Health Personnel↗
PubMed2003

"The lysis threshold": an erroneous and perhaps misleading concept?

The "lysis threshold" concept suggests that a lower limit of particle generation exists in total hip arthroplasty (THA) below which lysis will not occur or is tolerable. Although this concept is appealing at first, serious reservations arise with more detailed analysis. Five major points challenge this concept: (1) For many of the reports, the duration too short. Ten years is not the goal for most patients. (2) The definition of lysis is inadequate, listing only "balloon" lysis or endosteal erosion. (3) In most reports of 100 micro m/y, lysis does occur. (4) Plain radiographs are not adequate for detection of lysis. (5) Other factors can overwhelm the role of particle volume, such as patch-porous cementless femoral designs. These 5 observations seriously challenge the lysis threshold concept.

Arthroplasty, Replacement, Hip↗
PubMed1996

A concept analysis of panic.

Minimal attention has been focused on the concept of panic in the discipline of nursing. Hindering a greater understanding of panic is its lack of explication and development in nursing. To help remedy this situation, a concept analysis of panic was performed. The hybrid model of concept development was used, which consists of an initial theoretical phase, a fieldwork phase, and a final analytical phase. In the theoretical phase, after a cross-disciplinary literature search was done, existing definitions and measurement of the concept of panic were analyzed, and a working definition of panic was formulated. In the fieldwork phase, women experiencing postpartum panic disorder were interviewed to collect qualitative data for further analysis of panic. The final phase focused on comparing and contrasting the findings from the theoretical phase with the insights discovered from the fieldwork. Applicability of panic across nursing is addressed along with implications for nursing theory, practice, and research.

Anxiety↗